Hey there!
Your answer would be B. Turn it off by the power button.
When hibernating the system, it will appear to be powered off, but as soon as you tap the power button, it will resume activity. When using battery power, you are obviously not conserving any power. Sleeping the system will perform a similar function to hibernation, except it will resume activity upon pressing any key or moving the mouse.
I hope this helps!
- alxndr.
